"Stroke" or focal cerebral ischemia presents an extremely complex patho-physiological problem. Stated most simply, cerebral ischemia is the reduction or loss of blood flow to all or part of the brain with a subsequent reduction or loss of oxygen and substrate delivery to the tissue. As a cause of death, stroke ranks third after heart disease and cancer. When not lethal, it is associated with a type of morbidity which can ruin lives. leaving patients unable to cope with daily existence and imposing a heavy burden on the family and society. The disease's economic impact is staggering: for the year 1976, direct and indirect (lost wages) costs have been estimated to be 7.4 billion dollars. Accordingly there is an enormous need for providing a effective treatments for this disease.